What motivates Buck to fight for his position in the pack?

Buck's motivation to fight for his position in the pack primarily stems from his instinctual drive for survival and supremacy. In the harsh wilderness setting of "The Call of the Wild," every creature must assert itself within the pack hierarchy to secure resources like food and protection. Fighting for dominance becomes essential for Buck as he adapts to the brutal conditions and learns the importance of strength and strategy in ensuring his survival. This instinctual behavior reflects his transformation from a domesticated pet to a wild animal, where establishing one's rank is a critical factor for ongoing existence in such a competitive environment.

The other motivations, while they may influence behavior to some extent, do not capture the primary driving force behind Buck’s actions in the wild as effectively as survival and the instinctual need for supremacy do. Competitiveness, fear of abandonment, and the desire for power can play roles in his interactions, but they are rooted in his overarching need to survive and thrive in a challenging and often dangerous world.